As is generally well known in the art, there are various fastener devices of the push-on type which can be quickly installed upon a threaded stud but yet are required to be unscrewed with respect to the threaded studs in order to remove the fastener devices from the threaded studs. For example, in U.S. Pat. No. 4,571,136 to Brian R. Peek, wherein the disclosed invention was invented by the same inventor and assigned to the same assignee as the present invention, there is disclosed a one-piece plastic fastener which is designed to be pushed onto a threaded stud. The fastener includes a head portion and a generally axially extending cylindrical body portion. The cylindrical body portion is formed with a pair of diametrically opposed rib sections which extend the length of the body portion with the rib sections having equally spaced arcuate segments. Within the interior of the cylindrical body portion, a resilient wing member is integrally formed inwardly of the arcuate segments. A pair of longitudinally extending narrow ridges are also formed upon the interior of the body portion with a thickness selected so as to cause the resilient wing members to be brought into threaded engagement with the threaded stud as the fastener is pushed onto the stud.
The present invention represents a significant improvement over U.S. Pat. No. 4,571,136 which is incorporated herein by reference. In the present invention, there is provided an improved insulation retainer of the push-on type which comprises an outer body member, an inner body member, and means for adjusting the movement of the outer body member relative to the inner body member so as to accommodate various thicknesses of insulation to be secured to a substrate.